LDAP (Active Directory) Programming with C#

1. .NET Support 2 sets of classes of Active Directory(AD) operations.
2. System.DirectoryServices
   Older class, supports from .net 1.0. Supports all AD operations (setting password, enable/disable account, reterive AD objects).
3. System.DirectoryServices.AccountManagement
   Newer version (>=3.5), easier to manage AD operations. Usign UserPrincipal object to access LDAP object.
4. createDirectoryEntry Function
   
   static DirectoryEntry GetDirectoryEntryObject()
   {
     DirectoryEntry deObj = new DirectoryEntry("SERVER_NAME"); //SVR-MAK.DNS.local
     deObj.Path = "LDAP://SVR-MAK.DNS.local:389/DC=DNS,DC=local";
     deObj.AuthenticationType = AuthenticationTypes.Secure;
     //deConn.Username = "username";
     //deConn.Password = "password";
     return deObj;
   }
   username and password - no need to specify if you logged into a system as a domain admin
   
5. Search Filter to get all user's record.
   
   SearchFilter("Mo A. Ka");
   private void SearchFilter(String username)
   {
     try
     {
       DirectoryEntry deObj = GetDirectoryEntryObject();
   
       DirectorySearcher deSearch = new DirectorySearcher(deObj);
       deSearch.Filter = "(cn=" + username + ")";
       //search.Filter = "(&(objectClass=user)(objectCategory=person))";
   User Exist
   
       SearchResultCollection srResultsCol = deSearch.FindAll();
       Response.Write(srResultsCol.Count + "<br>");
   Find One User
   
       SearchResult srResults = deSearch.FindOne();
       if (srResults != null)
       {
         Response.Write(String.Format(srResults.Path) + "<br>");
   Get selected information from a user's record
   
         Response.Write(srResults.Properties["displayname"][0].ToString());
         Response.Write(srResults.Properties["mail"][0].ToString());
   
         ResultPropertyCollection rpcCol = srResults.Properties;
   Get all information from a user's record
   
         foreach (String field in rpcCol.PropertyNames)
         {
           foreach (Object objCol in rpcCol[field])
             Response.Write(String.Format("{0,-20} : {1} <br>", field, objCol.ToString()));
           }
         }
         else
         {
           // user does not exist
           Response.Write("User not found!");
         }
       }
       catch (Exception e)
       {
         Response.Write("Exception caught:\n\n" + e.ToString());
       }
   }
   Output
   
   LDAP://DNS-FPS01.DNS.local:389/CN=Mo A. Ka,CN=Users,DC=DNS,DC=local
   cn : Mo A. Ka
   mailnickname : mKa
   memberof : CN=DNS-SPUser,CN=Users,DC=DNS,DC=local
   displayname : Mo Ka
   sn : Ka
   samaccountname : mKa
   givenname : Mo
   mail : mKa@DNSsolutions.com
   adspath : LDAP://DNS-SVR01.DNS.local:389/CN=Mo A. Ka,CN=Users,DC=DNS,DC=local
   lockouttime : 0
   proxyaddresDNS : SMTP:mKa@DNS.com
   userprincipalname : mKa@DNS.local
   countrycode : 0
   lastlogontimestamp : 129579115667725093
   ...more...
   
6. Get All user's record information.
   
   DirectoryEntry deObj = GetDirectoryEntryObject();
   DirectorySearcher deSearch = new DirectorySearcher(deObj);
   deSearch.PropertiesToLoad.Add("cn");
   deSearch.PropertiesToLoad.Add("displayname");
   
   SearchResultCollection srResultsCol = deSearch.FindAll();
   
   foreach (SearchResult srResults in srResultsCol)
   {
     if (srResults.Properties["cn"].Count > 0 && srResults.Properties["displayname"].Count > 0)
     {
       String cn = srResults.Properties["cn"][0].ToString();
       String displayname= srResults.Properties["displayname"][0].ToString();
       Response.Write(String.Format("{0,-20} : {1}
   ", cn,displayname);
     }
   }
   
   
7. Modify user information
   
   ModifyUser("Mo A. Ka", "displayname");
   private void ModifyUser(String username, String property)
   {
     DirectoryEntry deObj = GetDirectoryEntryObject();
     DirectorySearcher deSearch = new DirectorySearcher(deObj);
     deSearch.Filter = "(cn=" + username + ")";
     deSearch.PropertiesToLoad.Add(property);
   
     SearchResult srResults = deSearch.FindOne();
     if (srResults != null)
     {
       DirectoryEntry entryToUpdate = srResults.GetDirectoryEntry();
       Response.Write(srResults.Properties[property][0].ToString());
       entryToUpdate.Properties[property].Value = "Mohideen A Kader";
       entryToUpdate.CommitChanges();
     }
   }